3INO

1.95A Resolution Structure of Protective Antigen Domain 4

Summary for 3INO

• Entry DOI: 10.2210/pdb3ino/pdb
• Descriptor: Protective antigen PA-63 (2 entities in total)
• Functional Keywords: anthrax, domain 4, protective antigen, toxin, calcium, cleavage on pair of basic residues, metal-binding, plasmid, secreted, virulence, immune system
• Biological source: Bacillus anthracis (anthrax,anthrax bacterium)
• Cellular location: Secreted, extracellular space: P13423
• Total number of polymer chains: 2
• Total formula weight: 32484.51

Authors

Lovell, S.,Williams, A.S.,Anbanandam, A.,El-Chami, R.,Bann, J.G. (deposition date: 2009-08-12, release date: 2009-11-03, Last modification date: 2023-09-06)

Primary citation

Williams, A.S.,Lovell, S.,Anbanandam, A.,El-Chami, R.,Bann, J.G.
Domain 4 of the anthrax protective antigen maintains structure and binding to the host receptor CMG2 at low pH
Protein Sci., 18:2277-2286, 2009

PubMed Abstract: Domain 4 of the anthrax protective antigen (PA) plays a key role in cellular receptor recognition as well as in pH-dependent pore formation. We present here the 1.95 A crystal structure of domain 4, which adopts a fold that is identical to that observed in the full-length protein. We have also investigated the structural properties of the isolated domain 4 as a function of pH, as well as the pH-dependence on binding to the von Willebrand factor A domain of capillary morphogenesis protein 2 (CMG2). Our results provide evidence that the isolated domain 4 maintains structure and interactions with CMG2 at pH 5, a pH that is known to cause release of the receptor on conversion of the heptameric prepore (PA(63))(7) to a membrane-spanning pore. Our results suggest that receptor release is not driven solely by a pH-induced unfolding of domain 4.

PubMed: 19722284
DOI: 10.1002/pro.238

Experimental method

X-RAY DIFFRACTION (1.95 Å)